1. Field of the Invention
The present invention relates to a cathode cartridge of a testing device for electroplating, and to a testing device for electroplating, more particularly to one that can plate uniformly.
2. Prior Art
Recently, plating technology has been applied in a wide range of fields, and has been especially noticed as a technology for forming a minute metallic object.
One these fields is the wiring technology of LSI, which is the so-called Damascene Process. In order to materialize higher integration and high performance thereof, reducing a pitch of wiring distributed on a semiconductor is required. The Damascene Process is a method in which channels for wiring are maintained after setting up layer insulation by carrying cut a dry etching process and then the wiring material is bedded in said channel by plating.
Moreover, as the latest technique of using another plating technology, there is a technique called as LIGA (Lithographie, Galvanoformung devices) to manufacture minute mechanical parts. LIGA is a technology by which acrylic resin is treated by X-ray, which is to be performed as molding processing, and then metallic minute particles are molded out of accumulating plating deposit thickly in the mold.
In order to materialize said plating technology, accumulating with uniform plating is required for a hollow dug place of a plating material. In addition, an appropriate plating condition is chosen by carrying out tests under any kind of conditions of plating solution and current density in a small scale laboratory level to be industrialized.
An object of the present invention is to provide a cathode cartridge and anode cartridge of a testing device for electroplating and a testing device for electroplating which can farm uniform film in a small scale testing device for electroplating.
To solve said objects, according to the primary object of the present invention, there is provided a cathode cartridge used in a testing device for electroplating, which comprises:
a tabular cathode conductor, which has an orifice having the same shape as a plated part of a plated base; the cathode conductor having a plurality of protruding portions that press contact to a peripheral part around the plated part, and which is able to connect with a direct current power supply by an exposed portion thereof not soaked in plating solution,
a tabular rear insulator covering both a backside of the plated base and a backside of the cathode conductor, and having a recess into which the plated base and the cathode conductor are retained,
a tabular front insulator having an orifice having the same shape as the plated part the front insulator covering a front side of the cathode conductor, and
an elastic thin board sandwiched between the plated base and the tabular rear insulator.
Owing to the above mentioned construction, because the cathode part can be intercepted by the invading plating solution, lines of electric force are generated between the anode and the plated base. Consequently a uniform plating membrane can be formed. And owing to the construction, in which protruding portions provided in a cathode conductor press contact to the plated base, accurate contacting of the cathode conductor with the plated base can be obtained. Moreover, since multiple protruding portions are provided, the lines of electric force can enter uniformly into the plated base, and a uniform plating membrane can be formed. The conductor in the present invention is an electric conductor which means a metal or a carbon, for example.
According to the second object of the present invention, there is characterized the above-described cathode cartridge to be connected with a direct voltage source by providing a conductive dummy plate having said shaped orifice to be a negative pole.
Owing to above construction, since the lines of electric force limited to only around the plate base can enter into the dummy pate from a plate side of the plated base, the lines of electric force entering into the plated base can be uniform. Consequently, a uniform plating membrane can be formed.
Furthermore, according to the third object of the present invention, there is characterized a testing device for electroplating, which comprises:
a plating tank containing plating solvent,
an anode provided in said plating tank,
a cathode which is the plated base provided in the plating tank and arranged parallel to said anode,
a scupper for the plating solvent provided on a bottom surface of said plating tank, and
exhaust holes for a plating solution provided on the bottom surface of the plating tank to circulate plating solvent around a surface of said plated base,
wherein a circulation pump is connected with the testing device in order to absorb the plating solvent from said scupper and to blow up the plating solvent from the exhaust holes.
Owing to above construction bubbles generated on the plating part can be removed and the density of positive ion around the plating part can be invariable. Consequently a uniform plating membrane an be formed.